INTEGRATED SCREW-SPINDLE COOLANT PUMP

Abstract

An electric screw coolant pump for integration into a temperature control circuit of an assembly of which the temperature is to be controlled. An accommodation housing includes a feeder line and a return line of the temperature control circuit, which open into a cavity. A part of the cavity surrounds a spindle housing and communicates with an outlet opening of the spindle housing as well as the feeder line. A sealing element, which provides a seal between a suction side and a pressure side, is arranged towards an end surface of the axial end of the inserted spindle housing.

Claims

1. An electric screw coolant pump for integration into a temperature control circuit of an assembly of which a temperature is to be controlled, comprising: a motor housing in which an electric motor is accommodated, a spindle housing, in which screw spindles are accommodated, with an axial inlet opening and a radial outlet opening; a housing flange connecting the motor housing and the spindle housing, an accommodation housing with an opened cavity into which the spindle housing is insertable from an axial end up to the housing flange; wherein the accommodation housing includes a feeder line as well as a return line of the temperature control circuit which open into the cavity; a part of the cavity surrounds the spindle housing and communicates with the outlet opening as well as the feeder line; and a sealing element providing a seal between a suction side and a pressure side is arranged towards an end surface of the axial end of the inserted spindle housing.

2. The electric screw coolant pump according to claim 1, wherein the return line opens in an end surface of the cavity situated across from the end surface of the axial end of the inserted spindle housing.

3. The electric screw coolant pump according to claim 1, wherein the sealing element radially surrounds a mouth of the return line and the inlet opening of the spindle housing.

4. The electric screw coolant pump according to claim 1, wherein the accommodation housing is integrally formed at a housing of the assembly of which the temperature is controlled by the temperature control circuit.

5. The electric screw coolant pump according to claim 1, wherein the screw spindles are mounted in a floating manner inside the spindle housing by means of a clearance fit.

6. The electric screw coolant pump according to claim 1, wherein one of the screw spindles and a shaft of the electric motor are connected by means of a plug-in connector with a clearance fit.

7. The electric screw coolant pump according to claim 1, wherein the spindle housing is delimited in an area of the inlet opening by a feather key inserted through a radial assembly gap.

8. The electric screw coolant pump according to claim 7, wherein the sealing element radially surrounds an axial area of the axial end of the spindle housing and seals the radial assembly gap of the feather key.

9. The electric screw coolant pump according to claim 1, wherein a sealing ring providing a seal between the pressure side and an external environment is arranged in a radial clearance between the spindle housing and the accommodation housing.

10. The electric screw coolant pump according to claim 1, wherein the housing flange has a bearing seat for a shaft bearing.

11. The electric screw coolant pump according to claim 10, wherein the shaft bearing is a sliding bearing bushing surrounded by a sealed lubricant filling.

12. The electric screw coolant pump according to claim 1, wherein power electronics are arranged inside the motor housing in thermal contact with the housing flange.

13. A temperature control device for controlling a temperature of an assembly comprising: an accommodation housing in which the assembly is accommodated; a temperature control circuit that is formed in the accommodation housing and which is in thermal contact with the assembly; the electric screw coolant pump according to claim 1 integrated into the temperature control circuit, wherein the accommodation housing is integrally formed as one common element of the temperature control device and the electric screw coolant pump.

14. The temperature control device for controlling the temperature of the assembly according to claim 13, wherein the assembly is a battery storage module having a multitude of battery cells.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The invention will be explained hereinafter with the aid of an embodiment and with reference to the accompanying drawing,

[0034] FIG. 1 shows a schematic sectional view through a screw coolant pump according to one embodiment of the invention.

DETAILED DESCRIPTION

[0035] The term “temperature control circuit” in the sense of this disclosure is to be understood to mean a delivery circuit for a coolant which is brought into thermal contact with an assembly in order to absorb waste heat of the assembly and to output it to a cooler medium such as e.g., the atmosphere. However, the manner of operation of the temperature control circuit is not limited to a cooling function. Thus, the temperature control circuit can also provide a warming function by means of a heat source during a start-up phase of the assembly of which the temperature is to be controlled.

[0036] The terms “feeder line” and “return line” of the temperature control circuit relate to how the assembly of which the temperature is to be controlled is viewed. Consequently, the feeder line of the temperature control circuit is connected to the outlet opening of the pump and the return line of the temperature control circuit is connected to the inlet opening of the pump.

[0037] In a temperature control circuit, a plurality of assemblies of which the temperature is to be controlled and which have the same or different functions can be incorporated into a plurality of modules which have a flow passing through them in succession or in parallel. Furthermore, a temperature control circuit can comprise a plurality of pumps.

[0038] The term “accommodation housing” relates, in the sense of this disclosure, to a housing body which is formed as a housing component or as an integral housing portion of a housing and which constitutes a component of the housing structure of the pump or of the assembly of which the temperature is to be controlled.

[0039] In terms of this disclosure, the term “screw pump” is understood to mean skew rotary piston pumps with a thread pitch for displacement of the medium to be delivered. Such types of pumps generally comprise a driven screw spindle and at least one further screw spindle which is in coupled motion therewith via engagement of the toothing.

[0040] The electric screw coolant pump 1 which is shown in FIG. 1 is arranged in an integrated manner within a temperature control circuit 50. The temperature control circuit 50 serves to control the temperature of an assembly 5 such as e.g., to discharge waste heat from the operation of the assembly 5 by means of a coolant delivered by the screw pump 1. In the following application, the assembly 5, not shown in more detail, is a traction battery for a battery-electric vehicle. Such a temperature control circuit 50 comprises a plurality of channels with a small cross-section which are in thermal contact with a plurality of battery cells.

[0041] In the embodiment of the schematic illustration of FIG. 1, in a spindle housing 10, a driven screw spindle 2a and a screw spindle 2b in coupled motion are received in a rotatable manner in a spindle chamber 12 of the spindle housing 10. A cross-sectional contour of the spindle chamber 12 is formed by two bores in the spindle housing 10, with overlapping radii, in order to ensure engagement of the screw spindles 2a, 2b. An open side of the spindle chamber 12 is delimited by a feather key 18. The feather key 18 is formed flat as an end-surface chamber wall of the spindle chamber 12 and has an inlet opening 16 of the spindle housing 10. The feather key 18 is inserted into the spindle housing 10 through a mounting slot perpendicularly to the screw spindles 2a, 2b.

[0042] The screw spindles 2a, 2b are mounted in a floating manner by a radial clearance fit with respect to the cross-sectional contour of the spindle chamber 12 and by an axial clearance fit of the spindle chamber 12. During pump operation, the spindles are pressed against the feather key 18 by the displacement process. The feather key 18 serves as a bearing shield with respect to the axial sliding bearing of the end surfaces of the screw spindles 2a, 2b.

[0043] A pressure side of the spindle chamber 12, which communicates with an outlet opening 17 of the spindle housing 10, is located on the drive side of the screw spindles 2a, 2b, which is depicted on the right. A suction side of the spindle chamber 12 is located on the other side of the screw spindles 2a, 2b on which the feather key 18 is disposed. The suction side of the spindle chamber 12 communicates with the inlet opening 17 of the spindle housing 10.

[0044] The spindle housing 10 forms, with the screw spindles 2a, 2b, an insertable pump head which is inserted into an accommodation housing 15 from an axial end of the spindle housing 10, towards which the inlet opening 16 is directed, up to a housing flange 14 which is connected to the opposing axial end of the spindle housing 10. The accommodation housing 15 is a component of the screw pump 1 and of the temperature control circuit 50. The accommodation housing 15 can at the same time be an integral component of the assembly 5 of which the temperature is to be controlled, such as e.g., a module housing of the assembly 5 in which the temperature control circuit 50 is continued in the form of integrated channels.

[0045] The accommodation housing 15 comprises an opened cavity 11 which receives the spindle housing 10 up to the housing flange 14. A return line 56 and a feeder line 57 of the temperature control circuit 50 open into the cavity 11. The feeder line 57 opens into a peripheral surface of the cavity 11. The cavity 11 surrounds the spindle housing 10 in such a way than an annular part of the cavity 11 is exposed where it overlaps with the outlet opening 17 and the mouth of the feeder line 57. FIG. 1 illustrates the outlet opening 17 and a mouth of the feeder line 57 directed downwards and orientated towards each other. In a deviation therefrom, both the outlet opening 17 and the mouth of the feeder line 57 can be orientated towards each other at any angles. The exposed part of the cavity 11 produces a pressure-side connection between the spindle housing 10 and the temperature control circuit 50.

[0046] The return line 56 opens into an end-face base surface of the opened cavity 11 and is allocated, in an opposing arrangement, to the inlet mouth 16 at the axial end of the inserted spindle housing 10. A sealing element 4 surrounds the mouth of the return line 56 and the inlet mouth 16 so that a suction-side connection is produced between the temperature control circuit 50 and the spindle housing 10.

[0047] The sealing element 4 also constitutes the housing-side seal between the suction side and the pressure side of the screw pump 1. During assembly of the screw pump 1, the sealing element 4 is pressed in, in a sealingly effective manner, by a tightening torque of the housing flange 14 against the accommodation housing 15 and compensates for axial manufacturing tolerances between the spindle housing 10 and the cavity 11. The sealing element 4 further surrounds a periphery of the spindle housing 10 in the area of the assembly slot, through which the feather key 18 is introduced. Therefore, a possible leakage flow along a plug-in fit of the feather key 18 is sealed. In the exposed cavity 11, a sealing ring 19 is introduced into groove-like radial free space upstream of the housing flange 14 in order to seal the pressure side of the screw pump 1 to the outside.

[0048] The driven screw spindle 2a is connected to an electric motor 3. On the pressure side of the spindle chamber 12, the spindle housing 10 comprises an aperture for a shaft 32 which is driven by the electric motor 3. A motor housing 13, in which the electric motor 3 is arranged, is connected on the opposing side of the housing flange 14. An internal stator 33 of the electric motor 3 is located on a collar portion of the housing flange 14. An external pot-shaped rotor 35 surrounds the stator 33 and is connected to one end of the shaft 32. A bearing seat for a shaft bearing 31 is formed internally on the collar portion of the housing flange 14. The shaft bearing 31 is a sliding bearing which is sealed at both axial ends and is filled with a lubricant. The other end of the shaft 32 is coupled to the driven screw spindle 2a by means of a plug-in connector 23 which allows axial clearance.

[0049] The motor housing 13 comprises a separated motor chamber, in which the dry-running electric motor 3 and an electronic system, in particular power electronics 34 for switching the electric power at the electric motor 3, are received. The stator 33 comprises field coils which are actuated by the power electronics 34 and supplied with electric power. The stator 33 is in thermal contact with the peripheral surface of the collar portion of the housing flange 14. Thus, waste heat from the field coils of the stator 33 is diverted via the housing flange 14 to the accommodation housing 15 and the spindle housing 10 and is absorbed by the temperature control circuit passing therethrough. The power electronics 34 are likewise arranged in thermal contact with the end surface of the housing flange 14 in order to discharge waste heat from the electronic components into an area of the temperature control circuit through which a flow passes.

[0050] The screw pump 1 is considered hereunder in a delivery direction of the temperature control circuit 50 in order to control the temperature of an assembly 5. A liquid delivery medium or a coolant is sucked into the spindle chamber 12 from the return line 56 of the temperature control circuit 50 through the seal 4 and the inlet opening 16 of the spindle housing 10 on the suction side. A rotational movement of engaged screw profiles of the rotating screw spindles 2a, 2b generates a negative pressure on the suction side of the spindle chamber 12 and a positive pressure on the opposing pressure side of the spindle chamber 12. The coolant is delivered by continuous displacement along a screw pitch of the engaged screw profiles and ejected from the spindle chamber 12 through the outlet opening 17 of the spindle housing 10. Downstream of the outlet opening 17 the coolant flows via the cavity 11 into the feeder line 57 of the temperature control circuit 50 and to the assembly 5.

LIST OF REFERENCE NUMERALS

[0051] 1 Screw pump [0052] 2a Driven screw spindle [0053] 2b Screw spindle in coupled motion [0054] 3 Electric motor [0055] 4 Seal [0056] 5 Assembly of which the temperature is to be controlled [0057] 10 Spindle housing [0058] 11 Cavity [0059] 12 Spindle chamber [0060] 13 Motor housing [0061] 14 Housing flange [0062] 15 Accommodation housing [0063] 16 Inlet opening of the spindle housing [0064] 17 Outlet opening of the spindle housing [0065] 18 Feather key [0066] 19 Sealing ring [0067] 23 Plug-in connector [0068] 31 Shaft bearing [0069] 32 Shaft [0070] 33 Stator [0071] 34 Power electronics [0072] 35 Rotor [0073] 50 Temperature control circuit [0074] 56 Return line of the temperature control circuit [0075] 57 Feeder line of the temperature control circuit